EXTRACTABILITY OF NICKEL ADDED TO SOILS AND ITS CONCENTRATION IN PLANTS

Abstract

The effect of Ni pretreatments on the yield and concentration of Ni in oats and alfalfa grown in four soils in pot tests varied with the rate of added Ni, with lime and phosphate treatments, and with soil properties, notably pH and organic matter content. The concentrations of Ni in the crops showing repressive effects of added Ni were at least 60 ppm in the oat grain, 28 ppm in the oat straw, and 44 ppm in the alfalfa. The amounts of soil-extractable Ni and the concentrations of Ni in the plants were reduced by liming of the acid soils and they tended to be increased by addition of phosphate. The effects of the Ni pretreatments on growth were less severe in a neutral soil and in one containing considerable organic matter than in the others.